1. Field of the Invention
The present invention relates, in general, to micro-electro-mechanical system (MEMS) packages having hydrophobic layers and, more particularly, to an MEMS package in which a hydrophobic layer is formed on a side sealing member that bonds and hermetically seals an MEMS element in the MEMS package, thus allowing the MEMS package to have an excellent seal to protect the MEMS element from the external environment.
2. Description of the Related Art
In recent years, various applications for MEMS and various products using MEMS have been proposed and practically used in a variety of industrial fields.
Most products, fabricated using MEMS, include mobile MEMS elements therein and have fine micrometer-sized structures, so that the MEMS products are mainly affected by surface-energy rather than mass-energy.
Thus, to provide MEMS products having stable and reliable operational performances, the MEMS products must have structures for protecting the mobile MEMS elements from the external environments, such as mechanical and chemical environment, and for isolating the mobile MEMS elements from a variety of environmental factors which may affect the surface-energy of the products. In an effort to accomplish the above-mentioned technical requirements, hermetic packaging techniques for the MEMS elements have been actively studied.
To hermetically package the MEMS elements, a soldering method using a metal soldering technique has been typically used in the related art.
FIG. 1 is a sectional view illustrating the construction of a conventional MEMS package, which is produced through a conventional soldering method and is disclosed in U.S. Pat. No. 6,303,986 (corresponding to Korean Patent Publication No. 2001-0053615).
In the conventional MEMS package disclosed in U.S. Pat. No. 6,303,986, a first solderable material 120 is formed on the upper surface of a passivation layer 114, while a second solderable material 124 is formed on the lower surface of a lid 122. The two solderable materials 120 and 124 are joined together by solder 126, thus sealing the MEMS package. The soldering method using the solder 126 creates an excellent seal for the MEMS package and imparts high operational reliability to the MEMS package.
However, the conventional soldering methods of producing the MEMS packages are problematic in that the soldering requires high process temperatures, difficult process conditions and high manufacturing costs.
In an effort to overcome the above-mentioned problems, MEMS packages having hermetic sealing members, such as epoxy sealing members, have been actively studied.